From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Analysis of clutch inertia, discussing raybestos friction rings, spinning parts, and a damped spring drive mechanism.
| Identifier | ExFiles\Box 125\2\ scan0055 | |
| Date | 14th June 1929 guessed | |
| contd :- -10- Figures are not available for G.4. and S.S. flywheels, which are somewhat lighter. The clutch has the friction materials attached to the driven member in the form of raybestos rings. The steel plate carrying these rings is only .075" thick. This arrangement was advocated recently by OY. and we estimate that the added inertia to equip the S.S. clutch similarly would be about .373 lbs.ft². We have determined the inertia of the whole spinning parts on an S.S. including disc, 1st. motion shaft and constant mesh pinion, at 1.016 lbs.ft², so that the increase would be about 37% on the existing parts. If the construction of the steel disc was altered, i.e., made thinner or in duralumin, this increase in inertia might be only about 20%, which would not be noticeable in our opinion. The driven member of the clutch is dished to the extent of approx. .050" as shown on fig.6. This is apparently to give a smooth take up. The unit pressure, neglecting the amount of this dish, is about 24 lbs/sq.in., and the total area of one ring 48 sq.ins. The raybestos makes contact with flat cast iron surfaces which locate the driven member endwise. The 1st. motion shaft has one bearing in the gearbox and spigots into the crankshaft, as in the 20 HP. DAMPED SPRING DRIVE. This is part of the driven member of the clutch as shown on fig.6. It has a range of movement of only ± 2°, which is probably less than the total twist in the transmission. It does not prevent the clutch from grabbing when taking up the drive, and we do not think it could really be intended contd :- | ||